The use of the mouse as a model system for understanding normal development and disease processes has increased dramatically over the last few years. This is due to sophisticated techniques that enable the manipulation of the mouse genome and the increasing number of genetic resources that have become available in the mouse for identifying genes that function in diverse biological processes. The goal of the proposed Cold Spring Harbor Conference on Mouse Molecular Genetics to be held August 28 to September 1, 2002, 2004 and 2006 is to bring together a diverse group of scientists studying various molecular and genetic aspects of mammalian development and disease. This conference is expected to attract approximately 400 scientists from around the world. This annual meeting will provide a format for the exchange of ideas and information among both junior and senior scientists, for the discussion of the latest research findings and technical advances towards the study of mammalian development and disease, and for fostering scientific collaboration. Eight topics (eight sessions) have been selected for detailed discussion as a reflection of the most advanced and interesting areas of study in mouse molecular genetics (Genetics, Genomics, Models of Human Disease, Patterning, Organogenesis, Signals & Receptors, Development and Function of the Nervous System, and New Technologies). Two established scientists per session are invited to present a relatively global perspective of their work (one of which will also act as the chairperson for that session), while the remainder of the talks will be selected from the submitted abstracts. Two workshops will be presented, one focusing on the preservation of mouse germ cells and embryos, and one focusing on BAC modification systems. Other participants are able to present their research in one of the two poster sessions to be held during the conference. This format allows the participation of many junior scientists, giving them a format to present their latest work.